This proposal is for continuation of support for an eight bed General Clinical Research Center and its associated laboratory and ambulatory clinic in a large medical center for children affiliated with Harvard Medical School comprising 329 beds with approximately 16,565 admission and a total of 258,015 outpatient visits per year. Our central goal in clinical investigation is commensurate with the mission of the institution which is to improve the health and welfare of children. We strive to understand the molecular and cellular basis of disorders that affect children and apply that knowledge to clinical investigation that will evaluate the efficacy of novel therapies. Our progress in the last five years indicates that we have improved the treatment in genetic disorders like Chronic Granulomatous Disease, Cooley's Anemia, and Cystic Fibrosis, impacted on immunodeficiency states and disturbances of complement metabolism, and established a treatment for Kawasaki Syndrome. Studies from our institution has established the molecular basis for Duchenne's and Beckler's Muscular Dystrophy. This work forms the basis for accurate diagnosis and provides potentially new therapeutic opportunities made possible only by the progress in understanding the basis of disease. We continued longitudinal protocols examining Isosexual Precocious Puberty, and Type I Glycogen Storage Disease as well as evaluating growth in children with Chronic Renal Failure and investigating whether beta cell rest may prevent type I diabetes in high risk individuals. The establishment of a sleep unit at this Center will allow for the development of novel protocols such as a neuroendocrine and sleep function study in adolescents with major depressive disorders. A considerable effort focuses on Central Nervous System sequelae of circulatory arrest during infant cardiac surgery. A major initiative involves the evaluation of combinations of various therapies in HIV infection as part of a natural study. The use of hematopoietic growth factors and cytokines in bone marrow failure syndromes, the evaluation of novel therapies in bone marrow transplantation as well as the use of alfa interferon in the treatment of life-threatening hemangiomas of infancy, all developed from bench research that ended at the bedside. We believe that our Center represents the most important mission of the Children's Hospital and utilizes the potential of its outstanding resources and environment.